This invention relates generally to conveyor systems and, in particular, to systems which receive packages in a cluster including side-by-side packages and which rearrange the packages into a single file, singulated stream.
In U.S. Pat. No. 5,415,281, which is commonly assigned with the present application, an article singulation conveyor is disclosed which utilizes tapered rollers which are driven at a uniform speed for the length of the conveyor but which produce a continuous speed increase laterally towards a vertical belt. The tapered rollers may be divided up into plural lanes of rollers. The speed increase across the conveyor bed tends to arrange packages in single file because one of a pair of side-by-side packages will move ahead of the other as both are urged in the direction of the vertical belt. The device disclosed in this patent is exceptionally effective if provided in sufficient length, such as 60-foot sections.
Some conveyor installations are restricted in the amount of space available for singulating clusters of packages. This is particularly a problem with modifications to existing installations, as well as new installations in existing facilities which are often constrained on space.
Rearrangement of clusters of articles into singulated single file is especially difficult for packages having one dimension that is significantly greater than its other dimensions. If several such long and slender articles are conveyed side-by-side, conventional article singulation conveyors have difficulty breaking up the side-by-side pair into single file. This is an especially onerous task in a singulation conveyor that is relatively short in length. Another problem that can occur is that packages having one long dimension can get oriented on the output of the singulation conveyor with the long dimension transverse the direction of travel of the conveyor. This can provide package jams, especially if the long dimension of the package is wider than a conveyor downstream of the singulation conveyor.
Thus, the need exists for a compact article singulation conveyor, or unscrambler, which is exceptionally effective in separating side-by-side packages into a single file of singulated articles without requiring a long footprint. Such a compact article singulation conveyor must be capable of breaking up pairs of side-by-side articles.
There also is a need for an article singulation device, or unscrambler, which has accumulation capabilities. System requirements typically specify a package throughput which the unscrambler must meet as a normal load and a much higher rate which must be met occasionally. While it would be possible to add additional unscrambler capacity in order to size the system to handle peak load, it would be desirable to size the unscrambler to meet normal, or base, load and incorporate an accumulation function in the unscrambler.
The present invention fulfills the need for a compact article singulation conveyor, or unscrambler, which is exceptionally effective in rearranging clusters of articles into a singulated single file of articles. The unscrambler may also provide accumulation to handle peak loads which exceed normal loads for which the system was designed to handle.
An article singulation conveyor according to the invention includes a receiving portion to which articles are delivered in random order including clusters of side-by-side articles and a discharge portion from which articles are discharged in a single file singulated stream. An article singulating portion is provided between the receiving and discharge portions. According to one aspect of the invention, the article singulating portion includes a first conveying member having a first traveling conveyor surface which travels longitudinally from the receiving portion to the discharge portion and a recirculation bed which removes side-by-side articles from a downstream portion of the first conveyor to an upstream portion of the first conveying surface. The recirculation bed may be made up of at least one peel-away conveyor having a second travelling conveying surface which travels away from the first conveying member to move side-by-side articles laterally off the first conveying surface. The recirculation bed may further include at least one coupling conveyor having a third travelling conveying surface which travels away from the second conveying surface upstream. The recirculation bed may further include at least one return conveyor having a fourth travelling conveying surface which travels from the third conveying surface to the first conveying surface. In this manner, clusters of articles tend to recirculate around the recirculation bed and the first conveying surface as individual articles of clusters are pulled away from the first conveying surface.
According to another aspect of the invention, the article singulating portion defines a generally planar circulus conveying surface. In this manner, with packages of non-uniform sizes, each identified by a machine-readable code on one side of the package supplied to the receiving portion with the machine-readable code in a particular orientation, packages can be unscrambled while maintaining the particular orientation of the package machine-readable codes. Additionally, such structure provides combined singulating and accumulating functions, whereby packages may be supplied at a rate which varies between an average rate and a momentary peak rate that is at least approximately 50% greater than the average rate by accumulating clusters of packages during rates that exceed the average rate and reducing the clusters when the rate returns toward the average rate. In this manner, peak loads can be accumulated on the unscrambler and the accumulated packages singulated as loads return toward normal.
According to another aspect of the invention, a package singulation conveyor includes a conveying surface traveling in a particular direction and a diverting surface. The diverting surface has at least a portion extending above the conveying surface and traveling upwardly and away from the conveying surface in a different direction normal to the particular direction. In this manner, when a package is traveling along the conveying surface having a portion which extends to the diverting surface, the package will be diverted from the conveying surface by the diverting surface. Because this aspect of the invention provides for diverting packages based upon contact with any portion of the package, the singulation conveyor removes side-by-side packages or packages which have a package dimension transverse the direction of travel of the conveying surface by operating on the transverse width of the package rather than on the center of gravity of the package. Therefore, even if the load is not distributed uniformly within the package, the package will be diverted if it is too wide in a direction transverse the direction of conveyor travel.
According to yet a further aspect of the invention, a method of conveying packages along a conveying surface includes providing a conveying surface and a diverting device, conveying packages along the conveying surface and diverting from the conveying surface with the diverting device, each package having a lateral dimension transverse the direction of travel of the conveying surface which is greater than or equal to a particular dimension. Any packages which are removed from the conveying surface are rotated and returned to the conveying surface. In this manner, packages which are rectangular with the long dimension traveling transverse the direction of travel will be removed and the packages returned to the conveying surface reoriented with the narrow dimensions transverse the conveying surface. The removed package can be returned upstream from the diverting device or returned to the conveying surface downstream of the diverting device. If returned upstream of the diverting device, it may be fed to an unscrambler in order to be processed along with other packages in a cluster. By reorienting packages which are traveling with the long dimension transverse the direction of travel of the conveying surface, packages which are too wide for downstream conveying surface dimensions will be reoriented in order to avoid jams and the like.